This invention proposes a device for making coffee, comprising a cylindrical chamber whose head walls have a number of pistons mounted on linear actuators of the screw and/or circulating ball type.
The walls of the pistons are made up of the same number of filters which allow the passage of hot water to obtain the infusion.
The new invention is characterized by a particular configuration of parts which forms a smaller overall unit, costs less, and is thus suited to applications in vehicles or for domestic use etc..
Machines are well-known for making coffee which have a chamber with a pair of moving walls worked hydraulically, and which have ducts for the conduction of hot water and for the removal of the coffee infusion.
A measured amount of powdered coffee is introduced into the chamber and is then pressed by the moving walls followed by extraction.
Because of the hydrualic mechanism for moving the walls these machines are mechanically quite complicated and consequently bulky and expensive. They are thus suited to high rates of output which limits their application to places such as canteens, factories or anywhere where there is a high rate of consumption.
Other machines of the type described above are also common, in which the chamber where extraction takes place has at least one moving wall which is activated by electromechanical devices comprising a motor and a transformer which works a mechsnism of cams and rods or the like, for compression of the powder.
These machines, though less expensive than the preceding ones, present greater problems in that their lifespan is limited, and they are in any case still quite bulky.